title: Exchange transfusion for severe malaria: evidence base and literature review.
abstract: BACKGROUND
  Exchange transfusion (ET) has biologic plausibility as an adjunct to antimalarial drugs in treating severe malaria and has been used for decades despite limited evidence of its efficacy in improving survival. We examined the efficacy of ET as an adjunct treatment for severe malaria using US surveillance data and reviewed the literature to update recommendations.
  
  
  METHODS
  Patients with severe malaria reported to the US national malaria surveillance system during 1985-2010 were matched, and survival outcomes were compared between patients receiving and not receiving ET. The literature review used search terms "severe malaria" and "exchange transfusion." Case reports and series, observational and case-control studies, and meta-analysis were included.
  
  
  RESULTS
  One hundred one patients receiving ET were matched to 314 patients not receiving ET. There was no statistically significant association between ET and survival outcome (odds ratio, 0.84; 95% confidence interval, .44-1.60). We found 87 articles, mostly case reports or series, showing successful use of ET, likely reporting bias. There were 12 comparative studies, most of which were retrospective cohort studies, underpowered with no significant differences in survival. A previously published meta-analysis of 8 comparative studies found no significant survival differences. Adverse events were rarely reported but included acute respiratory distress syndrome, ventricular fibrillation, and hypotension.
  
  
  CONCLUSIONS
  Despite rapid parasite clearance times resulting from ET, there is no evidence for efficacy of ET as adjunctive therapy in severe malaria. Adjunct ET cannot be recommended. When rapidly acting antimalarials, specifically artemisinins, become more widely available, the biologic plausibility argument for ET will become less relevant.
authors.affiliation: Malaria Branch.
authors.forename: Kathrine R
authors.initials: KR
authors.lastname: Tan
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Wiegand
authors.forename: Paul M
authors.initials: PM
authors.lastname: Arguin
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005078:Exchange Transfusion, Whole Blood / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000628:therapy*; D008297:Male; D012189:Retrospective Studies
keywords: exchange transfusion; malaria treatment; severe malaria